Hi Daniel
Menswear data is thin on the ground but you could try British Clothing Industry Association(BCIA) and National Statistics Office.
Not sure what the stats will tell you other than the Menswear sector is suffering shortage of sales like all other fashion sectors.
Research target menswear retailers,create a collection that will sit along side the other brands that said retailer stocks,show your collection,retailer will either buy or not.
No real need for statistical research, the menswear retailers are having a very hard time now, last thing they need is new,untried suppliers. The retailers need more customers rather than more suppliers, don't be surprised if the retailers don't commit to new suppliers in 2008.
With the UK now in recession(again) expect it to be very difficult to successfully launch any new business/collection now.Had you have done your market research BEFORE you started you would have realised that the Menswear sector are permanently in recession in the UK.
SORRY, but at least now you know what your expectations should be.
michael@designerhelp.co.uk