Garage gyms are awesome. I just finished putting mine back together after moving, but here are some old photos from it's glory days.
Since then, I've added a prowler II and an Ironmind Apollon's axle, along with some more bumpers and some odds and ends.
You're in the UK right? Only company I know over there is strengthshop, but from what I've heard they make good gear.
Once you get a rack and bench, you'll find out that there is always "1 last thing" you want. Home gyms become sprawling monstrosities, haha. For powerlifting future considerations, I'd think about a reverse hyper and safety squat bar next, followed by a prowler.
For cable work, along with racks that come with pulleys, Spud Inc sells the cables individually that you can just hook up anywhere. You might be able to come up with something similar at home.