Polo bike geometry + addons

Sharpen the front end up, use decent tubing, make the joins burly and don't forget about details (brake mounts, BB height, long track ends, semi-compact geo, etc).

Sub-£150 seems wishful?

My BB is very similar to Aufbruch's Yates to look at:

The Little Red Fire Truck

Sub £150 is insane. For that price you'd need to bulk buy in Taiwan. If a local builder is doing it, he can't be making any money, unless he's using shit tubes.