There won't be any download of copyright-protected music here.  

The CD "Mission: Impossible - Best of then and now" contains almost all music themes from both M:I-series ( '68 and '88) and is still available for sale. Search and you'll find.  

Soundcarriers I know of:

M:I Music-LP (Dot-Records DLP25831) and music sheet
Samples available here (external link)

French LP, 1987

The Best Of M:I Then and Now
Audio CD, 33 tracks.
Almost all original scores from the series! 
The best CD to my mind!

Music from Mission: Impossible
22 themes by Lalo Schifrin, Bruce Geller and others.
Nice music, but most scores are not recognizeable as music from the series. 

Single, 45 rpm 1968 (This one is from Spain - you can tell by the spelling of "Mision..."- but the singles of other countries look similar)

LP More Mission: Impossible, conducted an arranged by Lalo Schifrin

Japanese Single, 45 rpm feat. teh orginal soundtrack. 

Turkish Single Görevimiz Tehlike- Mission: Impossible, 1973

CD Mission: Impossible..and more,
The Best of Lalo Schifrin 1962-1972

CD Music from Mission: Impossible Anthology, USA 1994

Single CD, The Self Destructers - Mission: Impossible '88

Greg Morris even recorded his own LP.
The Title "For You" sounds like romantic music.

CD Music from Mission: Impossible, Movie 1996

CD Music from Mission: Impossible, Movie 1996

CD Music from Mission: Impossible 2, Movie 2000