Jericho the freelancer here

[Sir William]

It seems what you want is about 200 years or so after the first Crusade.  That'll give you the leg/arm armor you're wanting without the necessity of a full breastplate (which you said you didn't want), and you'd still use a shield, albeit slightly smaller than the heater shields of the Crusades.

[FreelancerJericho]

Think I might make a fantasy or non specific one first, then once I've been around for a while make a very time specific one.

[Sir Ulrich]

The helm you want is period for about 1300, the example it's based off of is called the Bolzano helm which I know plenty of what was used during that period. (heres a link to all kinds of great helms http://www.liebaart.org/helm ) Though the gauntlets you want weren't used till at least 1330. For that I would suggest a hauberk without attachable mittens. Though that helm type could of been used later as well as great helms were in use till at least 1330. If you want a visored helm you should go with a visored sugarloaf if you're doing that period. If you want help building a kit I can easily link you to places to get stuff for the best prices, I guarantee it. I am on Facebook if you're interested or you can PM me here and I can list where you can get everything. Though the first thing I would suggest would be a set of arming clothes then maille and helmets. Coat of plates were used as early as 1250 and most of the visby models date to 1290 which is more than close enough time to use the helmet you want. I also know where you can get a helm like that though shipping will be a bit.