Share dealing and spread betting account charges and currencies

[psycho]

Hello,

 

I am thinking of making my GBP spread betting account multi currency (initially adding USD) because I feel that the charges for trading instruments priced in USD will be cheaper from a USD account than a GBP account.  Is this correct?  For example if I wanted to sell USD and buy GBP, would the spread bet be cheaper in a USD account or a GBP account?  What about for commodities and US shares?

 

Secondly, if I open a share dealing account for US shares (for long term stock positions), would it be cheaper to fund this in USD so there are no conversion fees?  What would the commission rate be?  Will it be £8 converted to USD?

 

Will I be able to move money between my USD and GBP spread betting accounts paying the 0.3% conversion fee?

 

Will my USD accounts be considered as assets for trades in my GBP accounts so I don't have to convert for margins or is this too complicated?

 

Finally, I assume the spread betting account in USD will be the same as GBP from a tax point of view (i.e. no tax).  If I open the share dealing account in USD, what is the maximum amount of dividends I can earn before my tax return really start to get complicated (therefore necessitating engaging an accountant the costs of which will need to be taken into account)?

 

If there happens to be a tabular comparison that would be just great!

 

Many thanks in advance.