Unmarked, resprayed Peugeot frame, need help with wheel spec, chain ring and headset?

I bought a cheap old peugeot frame from a guy in brighton a few months ago.
The BB is one of the old french one's so im guessing its 70's, 80's. The BB is still strong as ever with no problems through to the cranks, pedals or 52 tooth chain ring, so im going to keep these as they are.

The frame however has been resprayed so I have no idea what size the wheels need to be?
I'm looking to get a strong sturdy fixed back wheel. Not sure on the chain ratio I need with a 52 on the front?
Iv got about £120 to spend on both wheels.
Then there's the headset on the front which needs replacing, this I have absolutely no idea about?

I'm new to the forum, so any help would be much appreciated!!

Thanks in advance,
Charlie

headset will be 1" threaded. Look on here for suitable gear ratio (type gear inches into search). I would imagine a 20t rear cog would be ok for a 52, can be hard to find bigger sprockets though. Wheels I would think would be the std 700c size.

The steerer threads are very likely 25mm x 1mm pitch and not 1" x 24 t.p.i. which will mean a french headset. If so, the stem is 22mm diameter and not 7/8". You can get English threaded forks and headset. Unless you are into old peugeots (I like 'em) or the frame is special and high quality, it may be easier to get another old frame with English threads.