Welcome aboard
Always good to see someone wanting to come back into ownership. They do get under your skin!
You really can't go far wrong with a TDI in the same 75hp guise that you had before. Don't be afraid of mileages over 150k, as long as there is reasonable maintenance history it should be capable of 200k or more. If you see any adverts in the usual online places, you could always post a link to them and ask for opinions - this is a very friendly and helpful forum.
I'd say the sweet spot is early in the 2003 model year - so a '52 reg, possibly an early '03 - when they got the larger 42L fuel tank, but still had the forged/cast lower wishbones. Later cars had a revised pressed steel design for these which often rusts out unseen from the inside until it fails. This to me is the single most important thing to watch out for.
Other points to check, the wiper arm joints get loose and it scratches the screen, which can need both to be replaced. Earlier TDI's like your previous Y-reg one have the Webasto pre-heater, which there's every chance that it isn't working, but you'll only find out at 7 degrees C or less. If you come across a TDI '90 (red 'I' on the TDI badge) it will have a VNT turbo and a dual mass flywheel, both are prone to failure and expensive to fix.
It would be a wise investment if you were to upgrade your account to access the Marketplace here. Click on your user name in the black menu bar, select Account Upgrades, there's a one-off PayPal fee for the princely sum of £2, and you're done.