your around the same hight as me and i currently ride a t-mag, thats 1000mm wheelbase (i think) I feel that i need a longer bike now i know more about trials, so i'm buying a zip, over the week off holiday ive been none stop riding and football and i can safely say ive got a fair bit of back ache and i think its from the short bike. I ride my bike and i think its crap lol, thats probably because i ride my mates (Zoo ) zoo! python quite often and that just feels like the tits when i'm riding it, its better for gaps, sidehops, wheel swaps. The only thing i find more difficult to do is to rear wheel up things, then again i only have ago usually in like 10 - 15 minute bursts when we ride town once a week and thats if it isn't raining! So to draw my post to a conclusion, i'd say go for a long bike and don't look back my friend