Welcome! What a lovely, thoughtful gift you are contemplating. It's always nice when a spouse supports their mate's hobbies.
First of all, color guides...for my money, the best one is the one made by Stanley-Gibbons, which can be found here (I don't know if Subway has it, but you can check):
http://cgi.ebay.com/ws/eBayISAPI.dl...380112898365
The advantage to Stanley-Gibbons' Colour Key is the fact that each chip has a hole punched in it so you can lay it right over the stamp to do the comparison, plus it stores so compactly.
As to stamp tongs, I find that they're mostly a matter of personal preference. I have used both the spade tip and the round tip, and I tend to favor the former; I have used the bent tips and found that I had to adjust myself to them, but then again, this is just personal preference, along with the question of metal type. Suffice to say that extra tongs are always a good thing, and my suggestion would be to just get him the same kind as he is already using, unless he has said anything himself about getting a different kind.
Magnifying glasses are always nice, also, and it doesn't hurt to get one that is at least 10x, power-wise. Better still is one of those magnifiers with the built-in lamp and a gooseneck like you see in labs, because this ensures always having good light for viewing.
As to storage, my advice is to just duplicate what he has. An extra album or two is always nice but remember to see if he favours any particular color or size. As to pages or stock sheets for Lighthouse albums and binders, I am not really an authority, but if you could measure the size of the sheet and state how many rows there are on the page, and perhaps even scan one, I am sure that there is someone else here more conversant regarding them.
I have found Subway to be pretty good as a supplier, and find them nice and quick, and have never had a problem with them. They usually have a catalogue that shows up every once in a while; a good idea might be to check around the house for them and see if he has jotted any notes, etc. in them.
One other suggestion I would make is to find some kind of a box that is sectioned off inside that would help him to keep all of his smaller stamp collecting things in one place. I am sure he would find this handy. Size and type are up to you, but I have even found suitable ones at the local dollar store made of high impact plastic, but even a small tool box would probably work, if he has a lot of stamp goodies, or maybe even a small tackle box used for fishing tackle with the pull-up trays, which could even be used to store stamps in once they've been sorted.
If you have any other questions, don't hesitate to ask. We have a lot of knowledgeable people here who can supply answers without fail.