Hoi kopite, welcome to the DSLR club.
You'll be wanting to take a look at the basic cameras from Sony, Canon and Nikon if you're going new on a budget - that's A200, 1000D and D60 respectively. There's others - older models still float about in stock in various places, but lets not confuse things.
If you're happy with the Sony, and there's reason why not to be for a beginner, then my advice is just to stick with the kit lens for now. A 75-300 lens is... Hmmmm. The Sony one that you'll be looking at fits in below the Canon and Nikon VR lenses, the Sony G which slots in above them is way out of budget for the moment. I'm not sure that you'll get much use out of it - apart from a quick trip to the zoo it's not really great.
What I heartily reccomend is to choose a decent starting lens and then give it a few months before you know what you're after - that way you won't buy and sell 3 or 4 times before you settle on a kit. Lens buying works kind of like this - if you buy budget lenses new you'll loose value when you sell on, if you buy quality lenses 2nd hand or new you won't loose very much - I've even gained. Buying a budget 75-300 will loose you about 70quid if you decide you don't like/want it - and it IS a budget lens - it's ok for the price but not great.
Bobster will be pleased to note that the A200 features a dedicated ISO button As to the control wheel on the A100 - I personally liked it - what other budget camera gives you access to (deep breath) metering mode, flash mode, focus mode, ISO, white balance, DR features, drive mode, EV compensation, AEL + slow synch and JPG shooting parameters/RAW mode without diving into menus? Yes - it takes a day or so to learn how to use all that power, but that's how Minolta's have always been designed - a button for everything. I have to say that I came from a Minolta A2 which also had that top wheel, so I'd had a few months to get used to it.
Quick note on the Sony system - the basic lenses are there but if you want T&S lenses or super-telephoto primes you should go elsewhere. Otherwise the lenses are excellent - in fact Sony beats out Canon for the lenses I use - their 24-70 2.8 & 135mm prime(s!!!) are all better than the Canon equivalent. Can't see the 16-35 2.8 being worse than Canon's either. It's been a while since the 135 f2 L was second best - I'm sure Canon users will agree that competition is a good thing
What you might regret is having to go 2nd hand for a few essentials (50mm f1.7 - but at least you get autofocus and the build is a lot better than the Canon's) and we have no 85mm f1.8 - only a selection of 6(!) f1.4s... The cheapest of those is about 300quid 2nd hand though - not a budget option. We also get our 3rd party options a few months after the Canon & Nikon versions - so if you want the latest Sigma or Tamron you'll have to wait a little - there's a LOT of people wanting the new version of the Siggy 70-200 2.8 which has only just started shipping in Sony mount. We also don't get the 200-500 f2.8 :'(
2nd hand? Yeeeeeeees......... Camera bodies fail. I've killed one and sent 2 in for warranty repairs - and I've got another waiting out of warranty til I get the cash. While basically reliable they're very complex and can be sensitive to lots of things. Both myself and a friend just spent a month bouncing about Mongolia with SLRs - a Dynax 7 and a 5D. We both reckon our cameras need tune-ups now - both of us reckon the AF is out of alignement. On the other hand maybe you're buying an unwanted birthday present? Shutter count is a good way to check but personally I'd be wary of a 2nd hand camera unless you know the seller, even though I'd take a new 7D over an A200 or a new 30D over a 1000D any day.
A lot of accusations of camera bias float about forums - I try not to get stuck in it. For the record I shoot a Sony A900, but I very seriously considered a D700 and am currently roaming Beijing trying to find a nice Nikon D80 set-up for my friend. If you want pros and cons of the other brands feel free to ask