I'm surprised you haven't found one you like or suits your needs.I use Gun Safe v2.8 by Kevin Kelly,and REALLY like it.It allows you to put TONS of info on the gun and any accesories, as well as pictures in ti.Take a look if you havent already.If you have, and didn like it for some reason (realted to the way its organized or such), the author states he used Filemaker Pro v5.5, so since that allowed him to setup a nice,user freindly format (IMHO), with dro-pdown menus, pictures, "fill in the blanks" areas, and open sections for whatever you want, it seems lke it might be able to do what you need, and you can customize any way you want.Just a thought, as I haven't ever used Filemaker Pro, and dont know anthing about it ther than Gun Safe was made with it, and I like Gun Safe, and it sounds like it would allow you to do what your looking for.Looks like Filemaker Pro 9 can be found here, with a free 30 day trial and purchase options.
http://www.filemaker.com/products/fmp/index.html
Filemaker pro 5.5 is here (kinda pricey though)
http://store.retrosoftware.net/13713.html
Gun Safe can be found here if your interested.
http://www.somanyroads.org/gunsafe/
I've never used acess, and my Excel sklls are weak, but it seems like you should be able to do whatever with it to (probly just not as fancy looking though), if you can figure out how to do what you want, as I don't find it too user friendy, but maybe it's just me.