Thanks for your help Jim!
I got a quote for $100AU to convert my tom into a snare, including all parts, hoops, snare action, skins etc. This would make my budget project a bit too much, especially since it's a percussion plus tom shell! I think I may just go for laying to 14'' tom down as a bass drum and making a micro kit rather than a cocktail. I may just use a 14'' inch pearl forum snare I have and have to 10'' tom as a tom.
All i'd need then would be a floor tom, perhaps i could cut down a larger drum to make it compact. I think i want to make each drum so that it can stack inside another, keeping the bottom skins off.