Shortblue, since the other idiots before tryed to affect me...now I am feeling obligated to reply here on topic

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So, why not try Barclays? They are Englih bank and one of their requirements is to be an english resident - that said, Yes, you can open account with 6000 GBP with them. Finally, I have some experience with them - can't complain. But...beware! Reading their terms and conditions they mention that you should be aware of liquidity risk - aka "risk that you cannot close your position due to lack of buyers/sellers" etc. Finally, you should be VERY aware of this thing. On NYSE and NASDAQ, SEC obligates these exchanges for every buyer to exist a seller and for every seller to exist a buyer - this is NOT the case for instance on the ASX (australian stock exchange). How about London stock exchange? Are there market makers/specialists?
You haven't mentioned that so far...so I feel obliged to mention it

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Other than Barclays, you can open account at Saxobank - BUT...I don't recommend it - their platform is terrible, my advice is to try with Barclays but read carefully their terms and conditions and ask them any questions you might have...of course.
Also, it is NOT possible to buy a stock in foreign currency and eliminate foreign exchange exposure prior to your value date. The currency will always move somehow until the value date or until your order is finally closed/settled. Yes you can lose money this way for instance:
100-(0.57/0.623752495)*100
Which equals about 8% possible loss/gain during your currency risk settles, in the case of a 500 pips move.
Finally, can't you simply convert the GBP to USD and trade mostly on NASDAQ, NYSE?
Of course our website offers opening of accounts in multiple currencies, but since "idiots" here like this stupid negger from Queens...well anyway.
write if you have more questions...
I'd personally go with Barclays.