> One is interested in early Georgian, and the other's persona is in the Varangian Guard (also an SCA Knight).
> Can anyone point me to reliable resources for research. I am planning to help sew & also to weave trim for these good gentles.
Depending on when and where your friend is interested in Georgia, he may be able to look at what the Khazars were doing and wearing, and he may have luck looking at some extant clothes from the northern Caucasus. (There is a famous site called Moschevaya Balka, which has turned up all sorts of amazing garments.)
There are some articles online that might help:
Prudence O. Harper. 2001. A Man's Caftan and Leggings from the North Caucasus of the Eighth to Tenth Century: Introduction
METROPOLITAN MUSEUM JOURNAL 36 pp.83-84
Nobuku Kajitani. 2001. A Man's Caftan and Leggings from the North Caucasus of the Eighth to Tenth Century: Conservators Report.
METROPOLITAN MUSEUM JOURNAL 36 pp.86-124
Elfrieder R. Knauer. 2001. A Man's Caftan and Leggings from the North Caucasus of the Eighth to Tenth Century: A Genealogical Study.
METROPOLITAN MUSEUM JOURNAL 36 pp.125-154
And doll's clothes (which might be miniature garments for the deceased to wear in the afterlife...)
I would also recommend you visit the mailing list of the Slavic Interest Group, as in the past they have had people interested in Georgia, and at the very least there may be something of use in their message archives.
For your Varangian friend, it might be worth clarifying if he is interested in a Rus' persona of a Slavicised Norse settler, or if he wants to be a Norseman working as a guardsman in the Byzantine empire. In either case, the more specialised Norsefolk list, http://groups.yahoo.com/group/Norsefolk_2
has information about it.
If you're more interested in wearing 'Eastern'-style dress from areas where the Varangians travelled, then the information here is a good start: http://www.miklagard.nvg.org.au/costume/rus/trader/rus_main.htm
If it's more 'what would you wear if you went native in Byzantium', there is a bit of information here, but I would personally emphasise the colour red:
Hope some of that helps?