I think its time to sack your 2nd dealer - he clearly knows very little about his business.
Headline wattage figures on amps should only be taken as a guide to an amplifiers ability, and they occasionally have very little to do with an amplifiers power or its ability to drive a speaker.
For example a high quality 30W tube amp can comfortably drive a full range speaker, whilst a cheap/underspecified 100W amp may struggle. The more important figure on amsp is (no pun intended) how many amps (amperes) they deliver, and the requirements of the speaker in terms of their sensitivity and impedence.
An overspecified amp won't damage you speakers per se, it will deliver as much or as little power as you tell it to when you turn the volume dial, otherwise monobloc amps capable of delivering 2000W into 4ohms would have no takers. Sure, if you turned that amp up beyond the operating capacity of your speakers, you would probably damage your speaker drivers, along with your ear drums.
Likewise, using an amp that is underspecified will lead to distortion as the volume in increased, which is more likely to damage your speaker drivers. Its always best to have slightly more power than you need to give your amo extra headroom. The 7005 should be fine driving all but the most demanding speakers, and at 125W with 2 channels driven, it is not going to blow your speakers for either lack of power or too much power.
As Big Boss, and your first dealer, has said, its always best to try and have a balance of components to get the best sound from your system.
I see you have bought the 7005, it is by all accounts, a very good amp. Is your speaker budget still £1000? And how many speakers are you after - 2.0, 5.1, 7.1?