PayPal's terms of service are so unsteady, I'd be extra cautious if you use them. Your best bet is to use an escrow or service that has a built in escrow system. That way, if they chargeback it's up to the Escrow to deal with. Some escrow services are as cheap as 3%.
If the .co.uk is older than the .uk, you can put in a claim and take the domain. Great for domainname hacks (like big.tr.uk) to own the .co.uk first and make claim later.
I'm looking for a short com domain including at least one of these words or combination of letters:
LC
LCS
SEC
CAM
SECURITY
WATCH
PROTECT
SECURE
SECURITY
I may be interested in other TLDs depending on how pronounceable or short they are. Registrar doesn't matter, I'll be transferring out...