Personally ide try one of the following

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=004

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=025

Or this for value for money

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=017

All these will put serious mass on with a good diet and training.You could also include other things once your happy with weight like Thermobol as a cutter to cut out excess fat (PM Godzilla as you WONT get cheaper Thermobol anywhere!!) and loads of other things but as a start one of the above would be good