Some retail stores are VAT registered, so you get around 16.7% off I think! Taking into account shipping, which will be around £35, your best bet is to look for a G1 bat which is listed at around 290 CAD (172 GBP). If you subtract the VAT and add on the shipping, it should cost you around 300 CAD. Hope this helps!
Based on what you've described, I think an Uzi is your best bet if you want a T20 styled bat for a 50 over player. You may be able to find a Players grade Uzi, which is G2, but if you go with a retailer who hand picks their bats, you're more likely to get one which performs really well.