Yo Apstyle!
Long time no post mate!
Couple of points -
I think by transferring large amounts in, you 'might' be liable for tax? - seeing as the loan is 'personal' funds coming in, I have a feeling it'll be subject to income tax. I'm not 100% sure though, maybe do some diggin around and ask over on the Tax section here and maybe Guya & Lizzit can clarify further.
I don't think Paypal is the cheapest option for currency exchange in large amounts although I could wrong especially as the direction is USA > UK. I've been looking the 'other' way UK>USA and other places and the specialist money currency exchange type places are the best bet for large sums of money.
Take a look at Moneycorp, HIFX etc as their rates are better than high st. banks etc and they seem to have good experience with sums being moved for property investment/purchase requirements.
Finally, you're looking to buy here?! I don't know your individual circumstances of course, however I'd advise you sit tight for as long as you can to see what the property market does in the next few months - many many buyers 'seem' to be following this as proeprty exhcnages are declining quite rapidly. If the USA does slip 'officially' into recession (amongst other possibles) , you can be pretty certain soon after it'll follow here.
That said, if you do come across something which suits you and you can afford it even if the market or outlook does indeed fall after the purchase, then go for it !!
Cheers mate!
DtM! West London & Slough UK!