Rear Beam Swap - North Herts

[C.A.R.]

I've managed to source a second-hand beam in good condition which I'll be looking to swap onto my car in the near future. It's lowered 40mm so I'll need to source some springs for the front end too just to balance the car out.

It's a straight swap and I've watched Darrens video on Youtube twice now, I'm just wondering if anyone locally would be happy to lend a hand? I have all the tools (I think) and can supply tea and biscuits.

I have a few questions also -
The rear beam mounts, should I replace these at the same time? It seems logical.
If yes to the above, which ones? Best value / quality
What things should I check at the same time? The new beam is being supplied bare, with no calipers (but it is a disc beam) and I'm not sure on this bit as in the video it was a drum beam to drum beam swap.
I plan to stick some yellow hammerite on it depending on the current finish, as mine is incredibly rusty for a Y-plate (never seen a beam rust before).

Thanks in advance.