The WELL MB-01 (Warrior L96) is a very good gun, but obviously will need upgrades. No sniper rifles are good out of the box.
They're one of the sniper rifles I recommend, alongside the JG BAR-10, which is a replica of the Tokyo Marui VSR-10 (I'd get the TM if you have the money)
I have an A&K M24, which comes with some good internals, but unfortunately I haven't had a chance to skirmish it yet. Nor have I got round to doing a review which I said I'd do, but disassembly proves harder than anticipated. Also I can't compare the performance to other sniper rifles since I have never shot any others.
If you wait until you've got your defence, order from a Polish retailer like TaiwanGun or Gunfire.pl and you'll be able to get it a lot cheaper than in the UK. Although there is £12 for shipping, they're only like 80 euros or something anyway.
But as Monty said, a bolt action isn't really the best choice to be honest. You'll see a lot of airsofters recommend against it for obvious kind of reasons.
First off you're outgunned by basically everyone.
As said above the need upgrades, otherwise performance won't be as you might expect. The same, or if not worse than an AEG in terms of range / accuracy. Only once you've spent quite a bit extra on them can you really see a proper improvement and advantage for using one over an AEG. But, that said, they are more fun and satisfying to use etc.
Another thing is that you might not find the play style enjoyable. Sniping is gonna involve sitting back, waiting for targets, whereas with anything else you can be up close in the action which is what most people want to experience and the thought is you won't get what you are expecting out of a skirmish using a bolt action rifle if you see what I'm saying.
+1 for a G&G Combat Machine though. Without a doubt the best you can get for your money, number 1 recommended gun on here. We always say new players should get one because they're great for the price.
Wish I'd known about them earlier and bought one myself, but rushed it and got a rubbish CYMA.
Best places to look are probably Land Warrior Airsoft, Airsoft World or Zero One Airsoft. The latter will have the best selection and according to their website the best prices on all G&G guns too.
Not only that but you also get a free skirmish voucher with your purchase.
Pro Airsoft Supplies did a transparent (therefore VCR Act compliant, no defence necessary) G&G CM16 and a package / bundle with the gun and a battery / charger for £120 but they might all be out of stock.
Same with Colchester Airsoft, but also sold out when I last checked.
Hope this helped mate and welcome to the forum!