I have searched for lower leagues but can not find any lower than the original database, I'm trying to find Romsey and have had no luck, does anyone know if there is a decent database on here and if it can link in with LFC Marshalls.
Big link at the top of the page saying Transfers. Then go onto Additional Leagues.
Lots of options on there. This is probably the most downloaded one (5575 dl's): Eng Lower Leagues V4 Level 10 + Cups + Awards - Downloads - Football Manager 2012 Tactics, Wonderkids & Cheats
I'd expect you can link it in with LFC Marshall's because there wont be any conflict, but couldn't be certain. Give it a try, if you enable both at the start of a new game and no error message is shown, you'll be fine