My front formula rotor has a slight warp my attempts at truing have only made it worse! I was going to get another formula rotor, just wondering if anyone had any other recommendations for other rotor brands or brands to avoid.

Unless you have any specific requirements, probably not worth worrying over. Got some cheapo Superstar rotors on my commute bike, no problems with them stopping me at junctions at the bottom of hills after not wanting to hold cars up.

I’ve had Shimano, Hope, Formula and Avid and the only ones that seem not warp are my Shimano with aluminium spider

£3 for a pair of genuine (well they seem to be!) Avid rotors on eBay. Even came with T25 bolts.
Had to wait 2 weeks for delivery from China, but for that price I’m happy to wait!