www.slingmeet.co.uk has most of the meets I think.
Different slings serve different purposes. Ring slings hold all the weight on the opposite shoulder to the baby, which I find great for quick trips eg from car to shop for a pint of milk but wouldn't be much good for a walk or a full supermarket shop. I used a stretchy (long piece of thick tee shirt type fabric) exclusively for the first 4 months then hired a woven wrap and learned back carries. The best thing about wovens and soft structured carriers (SSC) is that they spread the weight between your shoulders and your hips meaning you don't strain your muscles and making it much more comfortable for long periods.
DS is now 16 months and I alternate between "my" woven and "dp's" SSC. The woven is great to get him up and keep him up, for example in a shop where he might grab stuff, or if he's tired and needs cuddles. The SSC is fabulous when he might want to be up and down, like going to the park.
Narrow based carriers - the type most commonly available in the big baby shops - hold the weight on your back, between your shoulder blades. Placing all the strain there is manageable for the first couple of months, or for big burly men with broad shoulders, but is uncomfortable for the vast majority of people. There are also many many reasons on the internet for not facing your baby forwards - the best one I've found (and the easiest to actually prove!) is that it throws the parent's centre of gravity off so that you're more likely to fall or trip.
At 9 weeks I would suggest you look for a second hand stretchy wrap - Moby, Victoria Sling Lady, Close Caboo (which iirc is available from the NCT?) and loads of others I can't remember. That will be fine for the next few months - ignore anything that says they can be used for babies older than 6 months, they're tested for the weight of the baby but not the force at which such a small person can hurl themself if the mood so takes them! - while you research all the gorgeous colours, patterns and designs available, and also find which type suits you best and what you'll mostly use it for.
My current woven is Oscha Triskele Abram, which is turquoise and purple in a sort of wake effect. I've just traded our Rose and Rebellion (which was red with Jolly Rogers on) for an Action Baby Carrier (plain brown but I'm going to jazz it up with a panel, only got it Friday) :o
Epic post, sorry! One last thing - a woven can be used for very many different carries, including hip carries. So no need for a ring sling specifically unless you get addicted like most of us 