@Vladik: I'm in the US, not the UK. I just got new boots and blades recently. Unfortunately, it's not a great time to be buying boots and blades: shortages of many boots and blades, plus repeated price hikes. But such is life. I lucked out because the models and sizes (for both boots and blades) I wanted were available from factory inventory, so I got them in about two weeks; otherwise, it would have been 4+ months for the boots. I'll give you some background information (that I hope is useful), as well as additional recommendations (that I hope doesn't add to your confusion).
* John Wilson and MK were originally separate companies, but they merged in 1997 under the parent of HD Sports. So they are the same company now. My tech told me both Wilson and MK blades of all models have been in short supply because of supply-chain and production problems. You need to be extremely lucky for a retailer to have your model and your size in stock. If they have to wait for new factory stock, then who knows when you'll get it. Unfortunately, this holds for the MK Professional (Pro) as well as the Wilson Coronation Ace (CA). Not sure whether UK retailers have priority over retailers in other countries. For your sake, I hope so.
* At the same time, another major blade supplier, Riedell Eclipse, has not been able to manufacture new stock. Riedell is a US boot maker, but manufacture of their Eclipse blades was outsourced to Step of Canada. Step is well known for their hockey blades, and they also manufactured a line of figure skate blades under their own label (not widely sold), as well as figure skate blades for Riedell Eclipse and figure skate blades for Skate Science (which appears to be defunct at present). In recent years, though, CCM first purchased Step and then purchased Jackson (which supplies Ultima blades as well as Jackson boots). Since Jackson/Ultima are direct competitors of Riedell/Eclipse, CCM halted manufacture of Eclipse blades, and Riedell needs to find another manufacturer. So for now, skaters who want Eclipse blades need to luck out if their model and size is available from previous inventory.
* In the US at present, that leaves two dependable blade suppliers: Jackson Ultima and Paramount. Paramount manufactures their blades in the US. Ultima blades seem to be widely distributed in the UK, but I couldn't find a Paramount distributor in the UK (I did find one in Spain). All Paramount blades have the chassis + runner construction, similar to the Ultima Matrix line. The Paramount blades with stainless-steel runners are really expensive, but Paramount blades with plain-carbon-steel runners are competitively priced in the US. For example, the Paramount CA (their copy of the Wilson Coronation Ace) sells for $240, same price as the Ultima Legacy 7; Wilson CA and MK Pro sell for $300 over here. Prices will be different in other countries of course, depending on shipping and import taxes.
* Ultima, Eclipse, and Paramount sell blades "comparable" to Wilson and MK models. They are not true clones; "comparable" means anything a PR or marketing guy wants it to. The key difference is in the spin rocker profile. Ultima blades have the flattest spin rockers. Eclipse spin rockers are not as flat as Ultima but still flatter than Wilson/MK. Paramount is the only one I'm aware of that copies the pronounced spin rockers of Wilson/MK. I have the Paramount version of the Wilson Gold Seal.
* So here is my recommended list for you, in order of preference:
(1) Wilson CA [if available in your time frame]
(2) MK Pro [if available in your time frame]
(3) Paramount CA [If you can get it in the UK at a price acceptable to you. But also check that the sharpener you use has the equipment to sharpen it. Paramount, as well as the Ultima Matrix, needs a skate holder that can accommodate the thicker chassis.]
(4) Eclipse Aurora. Beautiful blade, made from 440C stainless steel. I previously skated on them. Traditional construction similar to the traditional Wilson CA. Only disadvantage is a somewhat flatter spin rocker. [Assuming you can get existing stock in your size in the UK.]
(5) Ultima Legacy 7. I put this dead last. In addition to the flat spin rocker, in the current Lite version, there are the slots in the sole plate and the body of the blade. Some skaters find the design to be cool. But I know a couple of skaters who have them. The slots trap slush and water. A real pain to dry off.