First, let me say that all three brands produce excellent planes, and you will most likely be happy with either.
This said, there is something to be said in favor of the low angle (bevel up) planes. First, there's no frog to speak of (at least not an adjustable one), so nothing to come loose or induce chatter if improperly machined. Second, if you hit gnarly grain you can increase the angle of attack by simply grinding a steeper bevel. You can grind a back bevel on a bevel down plane , but when it comes to sharpening the blade it's easier to have to work on only one side of the iron. If you need a lower angle, for shooting or working end grain, with a bevel up plane it's a simple matter to switch the iron for a lower angle one; with a bevel down plane you're out of luck, can't go lower than 45 degree pitch. In a nutshell, with a bevel up plane you gain versatility without sacrifice in performance.
Then there's the issue of the adjuster. Some people (lots of them actually) like the Stanley type mechanism, as it allows one to adjust depth of cut without taking the hands off the tote and knob. True, but over time the design of that type of adjuster wears and causes slop in the action, which defeats the advantage of having the adjuster at your fingertips IMHO. LN planes that I've laid my hands on seemed to be fairly tight in that respect, but all of them had seen little use. I have had the opportunity to try a Clifton smoother that had a few miles on it, and while the performance was there the adjuster was quite sloppy, like a couple turns of lash. Compare that to the Norris-type adjuster from the Veritas planes, none of my planes from that company have more than a quarter-turn of slop. I find it very unnerving to have to turn an adjuster back 2-3 turns to retract the iron a bit then 2-3 more turns forward to set the depth of cut...
When it comes to available funds, if the situation in the UK is similar to here in Canada, Veritas planes are noticeably less expensive than LN or Clifton (I suspect that Clifton is more affordable in your neck of the woods, over here they cost the same or more than a LN equivalent).
Given the choice, as Paul mentioned a smoother, a jointer and a block plane are the first three planes to get. I would suggest the Veritas bevel up jointer, excellent plane. I tried the LN #8 and loved it, but the price is just unreal, so I bought a vintage Stanley and replaced the iron and cap with LN replacements. I'm happy, for a third of the price of the LN...
And I would go for the Veritas low angle jack for a smoother. I like the extra registration of that plane compared to a smoother, and its performance and balance is wonderful. Think 5 1/2 instead of 4 1/2... Oh, it's also great for shooting...
For a scrub, I have the Veritas and like it very much. If you want to save some money you could buy a cheap import and grind a heavy camber on the iron. Not as good but not as expensive either, and it will do the job.
Block planes... The LN 60 1/2 is revered as "the standard" in its class. I have one, don't care for it, I might even sell it and get the Veritas (the tote and knob attachment turn it into a small smoother, I tried it and it works very well). I love the apron plane, but the mouth is not adjustable.
And you will want some kind of joinery plane at some point. I'd recommend a large shoulder plane, they're all good (Veritas, LN and Clifton), but the Veritas is more user-friendly according to reports.
By now I probably sound like a walking advertisement for Veritas planes... I don't own stock in the company (wish I did, though :lol: ), but I like the fact that the company does more than just spit out quality reproductions of old planes, and actually does something to improve on what has been done in the past. Innovation, you know...
HTH,
DC