New guy looking to build a Roman era kit.

[A_Volpe]

I was also going to suggest Mid Atl. Class. Soc in NJ which now does Leg XIII Gemina http://legioxiii.weebly.com/

As well as Leg XXIV and of course my unit, Leg III Cyrenaica.

Leg XX is the best place to start for not only finding the best gear to buy, but also how to make your own. It's not as difficult as it seems. larp.com/legioxx

Caligae I'd suggest Par Fabrica (but see if he can use conical hobnails not flat?), or if you can find them, "Castleford" or "Mainz" style caligae from Danyial Steelcrafts. The company recently had a parting of ways internally, so last I knew, there's like two different companies with the same name? Soul Of The Warrior might still have them.

I'd advise not to worry about having "everything" for your first event. Start with the basics - "Soft kit", being tunic, caligae, belt, then add on stuff like gladius, pugio, helmet, shield, then think about armor.
Raid used clothing, used/salvage fabric stores, utilize coupons and sales and the scraps bins.
I would suggest to invest in quality leather from places like Tandy, although you can come across some amazing bargains from places like consignment stores for say an old beat up leather jacket for things like leather scabbard covering, or patches, or small bags/pouches, etc.

Auxiliary can be a good starter, as body armor may not be as "standard" as previously thought, but, we also don't have anything that tells us how often and for how long (during the day) Legionaries wore their armor. It appears they really only wore it when they were route marching or going into battle. Otherwise, they possibly hardly ever wore it. We as modern reenactors and enthusiasts today may be wearing the armor far more often and for longer than the actual Romans did. But, of course, you invest heavily in the stuff, and, how many chances does one GET to wear super-cool armor all day? So, that's fine and good, but what I'm saying is don't feel like you have to have Everything Right Now. You could also portray a Tiro recruit, who may not have any body armor, but just starting (their training) in tunic and belt. Since you're just starting off in the period, it'll be an "accurate" portrayal in more ways than one. I'd also like to point out while the Balteus with the "danglium/dangly straps" is VERY common for soldiers in the 1st century, IMHO I think it's totally OK to start off with a basic balteus itself, with some decorated plates, and then add on or re-work the belt to have the added dangly straps later. It's quite possible it's what some Roman soldiers did, too.

For books, I highly recommend "Roman Military Equipment" by Bishop & Coulston (there are SO much stuff you can copy, the book is worth its weight in platinum); "Roman Military Dress" by Graham Sumner (also available in a 3-part series through Osprey); and "The Complete Roman Army" by Adrian Goldsworthy as a General Reference. General Roman information I'd recommend writings by Richard Alston (i.e. "Aspects of Roman History 31BC-AD117, Routledge press)
Do not get anything by Dando-Collins.