Well, first of all, there is nothing wrong with a good floorstander. Generally they will take up the same amount of space as a smaller speaker plus a stand, and deliver better bass. It is true that cheaper floorstanders can often sound boomy, since it takes a better bass driver to deal with the extra air in the box, and it's awfully hard to build a floorstander under a grand with a decent bass driver. Look at the cost of the really good floorstanders from ProAc or PMC and you'll see.
But in your exact situation, I can understand why the 'experts' are pushing you towards stand mounted speakers - and it isn't because of 'extra detail' (an oft-cited, but only sort-of-true, advantage of standmounts). Here are my reasons why you might be on the wrong track looking at standmounts:
1. Your budget. A grand or so can get you into a higher range on small speakers, but not bigger ones. For example, you could afford ProAc Studio series standmounts but not floorstanders. You could buy PMC DB1s but not any of their larger ones. Taking smaller speakers gets you better speakers - not because standmounts are better but because of where your budget falls.
2. Your room. Floorstanders - especially cheaper ones - need more space or they sound boomy. You have a smallish room and you don't have much positional flexibility. A floorstander close to the wall is not ideal. Read the reviews on WHF - nearly always, they will tell you that floorstanders need some space to perform their best. You may not have the ability to position them where they belong, and so you won't get the benefit of the bigger boxes. (For this reason, if you do buy floorstanders, you MUST get an in-home demo - they will not sound like they do at the shop in your room)
3. Speaker design. Floorstanders can give better bass, and thus throw up a big soundstage - but they get their better bass due to the additional space inside the box. They only way for a speaker designer to make use of the extra air, though, is to build a ported (bass-reflex) box. This is why they need space - the port output is reinforcing the low end by blowing air out at a specific tuning. If you put it close to a wall, the room modes will make the bass sound like a single, thumping note. You get more, but crappier, bass. Standmounts may have the same problem - but some standmounts are sealed boxes (or transmission line like the PMCs) and even ported standmounts give you the option of stuffing the ports to control the bass. You can't stuff a floorstander because there is too much air (a sealed box will always be smaller in volume than an ideal ported box for the same driver). You simply have more options with a standmount.
Since you need to put these close to a wall, a sealed speaker might be a better option. There will be less bass but it will be better behaved - and your smallish room will give you some room gain.
My advice is to try some standmounts before you make a final decision, and make sure you try some non-ported options. I would absolutely audition the be ATC SCM11s, which are slightly over budget but you said you'd be willing. WHF loved them and they are very well-behaved sealed boxes. I love the PMC DB1s which are tiny but have surprising (and accurate) bass.
You just get more for your money, more flexibility, more options to control the bass, and a better match for your room with smaller speakers.
Best of luck! Take your time, and don't forget to look at used speakers if you want to go higher end. Doesn't have to be eBay, plenty of dealers have used kit they will stand behind. If you went with the Naim and could find some used (and front-ported) ProAc D twos, you would be a very happy man - and your system would be light years better than if you bought cheap floorstanders.