I would recomend Capital One.
If you cant get a credit card with capital one then you will struggle with anybody else.
Even if you fail with capital one, they offer you a test period where you have a card, then you put £250 on it and supply your own credit limit.
Once you have shown you can stay within the £250 and make payments on time, (usually between 3 and 6 months) then they will raise your limit to £500 then £1000.
This would be a great way to get your credit back on side.
Secondly, if you only have 6 months to go before they are paid off, sit it out, get them paid and the accounts satisfied and this will do a world of good on your credit history.