and also, it may be a silly question, but does the white boot and the equivalent size in the black boot have any differences other than the stiffness?
With respect to Jackson separate boots for which there are men's and women's counterpart models:
(1) The men's model is stiffer than the women's model.
(2) The men's model is black, with no crystal adornment. The women's model is white, with crystal adornment.
(3) At least in the US (where I am), the men's model costs more than the women's model.
(4) Sizing designation (length and width) differs for men's and women's models. For stock lengths, there is a straightforward conversion: men's size X = women's [size X + 1.5]. E.g., men's size 8 = women's size 9.5, with the constraint that the maximum length for women's is a size 11 (corresponding to men's size 9.5), whereas the maximum length for men's is a size 13.
The range of stock widths, however, is different between men's and women's. Jackson width designation is messy to explain. A key point is that, although there is overlap in width range between men's and women's, women's are available in a narrower width than men's, and men's are available in a wider width than women's. If it is indeed true that your 'forefoot is quite wide' (needs to be confirmed by measurement) and you want black, then men's might be a good choice for you. But see next bullet.
(5) Where I am in the US, higher-grade men's boots are generally not stocked; they need to be special ordered. Women's boots are more likely to be stocked. But in another thread, a male skater in Australia found a shop that stocked men's Jackson Premieres. If your shop in Hong Kong stocks both men's and women's models, then you're OK. In many US shops, there is a return fee for special orders if you don't buy them; so it gets expensive to special order a bunch of boots to try on. See what the return policy for special orders at your shop in Hong Kong is.
Above, I referred you to another thread in which I discussed fitting tips. It is important that the heels fit properly with the boots straight out of the box, without adjustments. So if at all possible you want to try them on at the store.