US to UK Transfer of Funds

i need to transfer about $18,000 USD to the UK.  i am looking for the best way to do this (from a tax perspective). i have a UK accountant who's RUBBISH, and am looking for a new one.  hopefully i'll find one soon.

the reason i ask this online is that the new tax year is coming up and if there is an advantage to moving this money over in two chunks (one before the end of the year and one after) then i'll do so.

some of this money is already taxed income in the US, currently in a US checking account.  some of this money is CD's which come to maturity soon.  some of this money will arrise from selling of US mutual funds. 

advice?   

I recommend the fry group to explain how to "clean" capital.  It may not work for you, but it's a good starting point.  They will of course charge fees for their advice. 

www.thefrygroup.co.uk