First, WHY does it have to be shielded? This is not necessary unless the speaker is within 1 foot of an old CRT Tube type TV.
I has some large 12" woofers that were less than, though not my much, 12" from my CRT TV and never had a problem with magnetic interference.
So, again, unless the speaker is literally right next to a CRT TV, you don't need shielding.
In the roughly $300 range are the Tannoy Mercury F4. These were on deep discount a few months ago and many people here snapped them up, and we extremely pleased with the speakers.
The Q Acoustic 1050i is also a design similar to the Tannoy, and in the same price range.
You already know about the Acoustic Energy Neo-3 for about £200. I suspect these would be extremely good speakers for the price.
Now, since this is in a combined Kitchen/Dining area, can I assume these are more or less for background music, or general listening?
If so, you may not really need huge speakers. For the extremely low price of roughy £150, as mentioned by others, you can get the Wharfedale Diamond 9.4, which is a floorstanding speakers with a single 6.5 inch woofer. (AVBristol.co.uk , SuperFi.co.uk , and others )
These are actually larger than the well liked well respected Diamond 9.1. The 9.1 is a bookshelf with a 5" woofer. The 9.4 is a floorstander with a 6.5" woofer. A 6.5" woofer is about 1.7 times bigger than a 5" woofer.
Wharfedale 9.4, granite slabs and flatfeet
Scroll down to post number 8 to see a photo of the 9.4 in place in someone's house.
Now if you could possibly push to £370, you can get the very substantial Diamond 9.6. These are a true 3.5-way speaker with twin 8" woofers. (SightAndSoundUK.com )
Also, the new Q Acoustic 2050 is about £370, which is the new improved version of the 1050i.
It is worth calling several dealer to find out what the current prices are on the Monitor Audio Silver RS series speakers. These are available for about HALF their normal discount price, but I don't see them advertised anywhere. To get the deal, you have to call and ask. These are stunning speakers.
One additional point. One of the members here in the group went to Richer Sounds and listened to several speakers in the £100 to £150 range. He was most impressed with the sound of the Cambridge S30, which is a small bookshelf speaker.
While it was the most expensive in the test, he implied that it was well worth the extra money. In view of that review, I would say that the larger Cambridge floorstanders are well worth giving a listen to.
I also notice that Richer Sounds has Mordaunt Short 916i speakers on sale for £299, available in several finishes. That is also a speaker well worth listening to. I've never heard a bad word against Mordaunt Short. Most people are very impressed and pleased by their speakers.
In terms of 'easy to drive', that is more determined by Sensitivity. The closer to, and farther above, 90db the sensitivity rating is, the easier they are to drive.
You would only need to consider impedance if you are placing more than one speaker on each amp channel.
Steve/bluewizard