System Balance: How Refined an Amp?

My study/computer room is proximate 10x12---and crowded. I've Paradigm Atoms on top of 40" bookcase, 6' apart. To get started, I've been using the Sonic Frontiers T-Amp & Phillips PCD. I listen to indie rock & small ensemble classical.

I've been puzzled about how refined (how much to spend) for integrated amp. Plausible range might be NAD315ee, DussunDS99 http://www.aaa-audio.com/index-products-dussun.htm -- top out, for example, with Exposure or Naim.

OTOH, my first thought was to build Dr. Bottlehead's S.E.X (Single End Experimenter Kit),

http://www.bottlehead.com/et/adobespc/S.E.X./SEX.htm.

Dan Schmalle's instruction manual very convincing on the matter of getting seriously hurt---especially during verification end-phase. (Keep left hand in pocket, else current can arc through your body). Suitably scared me off. Still, a DIY project appeals to me and no one at DIY Audio Asylum has worries about 2 watt triode.

The data points on cost: NAD:=$350; Dussun:=$600; Exposure 2010S=$1400, Naim Nait = $1600. And Dr. Bottlehead's S.E.X. = $370.

Re sound source: I'd go one of 2 ways. Either Oppo (or NAD entry) or desktop PC build install sound cards or M-Audio USB outboard sound processors (research needed).

(Embarrasing on re-read. No one, I think, buys a >$1000 integrated to drive Paradigm Atoms in 120 sq. ft room.)

Well thanks for reading and I'll appreciate everyone's comments.

Many thanks,

Richard Moss