Have a look at the Wasp Uniphoxx, really good little frame that can take flat bands or tubes and can be set up to shoot OTT (over the top) or TTF (through the forks). I got the band clips for mine too which makes it really easy to change bands around (https://www.waspslingshots.co.uk/standard-slingshots-1). Katchum's recommendation is good too, I think i'm gonna have to bag one of them scout copies myself now haha!
Honestly mate, modern cattys are a million times better than black widows are. There's loads of good stuff on Youtube that you can learn from and a lot of good lads into it wh