Without LLU availability your options are, indeed, limited.
They're also quite limited if you're looking for an all-in package at around the same price level (around £30).
I would have suggested, in no particular order: -
1. Plusnet. Currently they are offering 60GB broadband (unlimited off-peak) for £21.49/month (in Market 1 exchanges) - £14.99/month for the first 3 months, plus £11.99/month line rental (including evening & weekend calls), so only £2.50 a month more than you're currently paying, but with a much higher usage allowance.
2. ADSL24 (£19.90/month for 30GB peak/unlimited off-peak; plus £12.90 line rental - no inclusive calls but calls are cheaper than BT and with no call connection charges - BT charge 12.5p for connecting each chargeable call).
ADSL24 are shortly due to launch an all-inclusive calls, line rental and broadband product.
3. BT - a bit more expensive than the other two, but for £38/month you get unlimited internet usage and free anytime voice calls.
Wouldn't recommend Talk-Talk unless your internet usage doesn't really rely on high download speeds (which appears to be one of their problem areas).
I don't really know anyone who has a Talk-Talk connection provided via BT Wholesale (i.e. not using Talk-Talk exchange equipment).
ADSL2+ with BE
DL Sync around 4.8Mbps
UL Sync 1088kbps
DG834GT with DGTeam firmware