using "of the rack" and custom suits for years, i cant really agree. yes the custom might fit better, especially if you are sized in a way thats usually kind of in between the usual sizing. by not overstretching material from start it keeps you warmer. beside that, sofar every suit was more or less "done" within a year. if you have a high quality of the rack or a good custom your 5mm will be about equivalent to a 3mm if it is substandard material it might be insulating like a 2mm. still usable as an undersuit or warm water suit. while having used billabong and camaro for years, i dont see any "out of normal" probs with the HH suits. of the rack fits me great, so no real point to waste money on custom suits (well give me a good deal and i take it). good suits are not cheap period, nothing to do with fitted or not, neoprene comes in many qualities and gets expensive fast if you dont use cr*p. as example a custom camaro cost not much more than a standard (we talking $50 to 100) same material, maybe a couple more zippers and stuff at your choice.
by the way, if the shallow side of your deep dives is at about 200 to 250ft - you might wanna consider drysuits considering deco times, total divetime and the usual heatloss. i couldnt imagine, even here in the caribbean, to do any dives where the shallower end is in the 200ft range to use anything less than a semidry (and thats getting friggin cold in the end).