Please don't apply to regional firms just because you think your grades aren't good enough for City firms. That would be a very bad idea. The whole culture and working environment of regional firms are different to City firms. That's generally why you get questions on applications like "What makes you think you're a City lawyer / Why do you want to be a City lawyer" and in comparions questions like "What are your links to this region".
I would suggest to you OP that you research exactly what area of law you want to work in, go to a range of Open Days with both City and Regional firms and really get a feel of the differences between such firms. Then make up your mind where you want to apply. Also, applying to firms with regional offices and hoping to transition is also not a good idea either. As I was told by one US firm "Don't apply to the London office if you want to transfer over to the States." That may not be a direct comparison but the principle is the same. If you think about it, the London office of a regional firm will be taking in trainees that will qualify into that office, it will be unlikely that they'll save space for those that want to transfer to other offices. Therefore, it is very important that you research and know you'll be happy in both City and Regional law firms if you are applying to both!
With regards to city law firms, I can only encourage you to NOT be put off by the A-Level requirements. You are on track for a 2:1, yes you got a 2:2 in 1st year but you've pulled it up in 2nd year. Equally, an ABB will not stop you from applying to top firms. If you have the urge that you really want to apply to MC firms or US firms, look at how flexible they are with their academic requirements (is it "You must get AAA/B or we won't even look at your application" or is it not that blunt on their website?) and just apply. If you have good extra-currics and interesting things you've done then apply and you may be surprised at what you can achieve!
EDIT: I just realised that I hadn't answered your original question. If you are doing a law degree, then your lack of vac schemes will be more obvious to HR. This is because generally all law students looking to go into law will have applied in their 2nd year. But if you're going into your 3rd year, then I would say apply for a mixture of vac schemes and TCs - that would be your best bet.
Vac schemes are still important and as someone still at uni, your chances will be greater at getting them now. In my experience, it is much harder to get them once you're out of uni / studying phase. Also my experiences are that the only people I know who have got straight TCs without any vac scheme experiences were people who graduated from Cambridge and even one of them had some sort of informal work experience. However, none of them did law degrees.
So apply for both vac schemes and TCs in this round of applications!