Best places for scholarships - well , your university may offer some. Take a look at engineering/physics institutes and academies - IoP, IMechE, IET, RAE, RAeS, IMAResT, IChemE, RS, that sort of thing. MANY will offer scholarships - some will be for high potential candidates, some will be for a project you've done in your spare time. Most will offer funding for "hardship," which may or may not count you out based on your parents' situation, but generally, they're a lot easier to bag than people think, and highly undersubscribed.
Finally, some companies or the armed forces may sponsor you - these can be hit and miss, and often have contractual clauses whereby if you don't join them, you pay the money back, but there are sponsorships which have no strings whatsoever - their downside is that the company don't have to take you on and hence you don't have a guaranteed job.
Sheffield, Leeds, Southampton - they're fine. Any Russell group university will be recognised well by employers, and you'll find the aerospace bunch aren't nearly as snobbish as the Eton fraternities that run their own (small) hedge funds and only let "members" work for them. Generally, if you have good aptitude, it will not matter where you went to university, provided you have that 2:1+ piece of paper at the end, but the research projects you'll work on will be so much better, interesting and industry relevant at a well funded, research-led university, hence choose Russell group if you can.
Stu Haynes MEng MIET MIEEE