Witch speedmaster Mark IV should I buy?

Hi there,
I am interested in buying an Omega Speedmaster. My favourit ones are the old MARK IV watches.
I saw two nice second hand watches in the internet:

1).
OMEGA - SPEEDMASTER AUTOMATIC MK. 4,5, Ref. 176.0012 Original Cal. 1045 - 1979
http://www.omegawatches.com/spirit/history/vintage-omegas/vintage-watches-database?ref=14297

2).
OMEGA - SPEEDMASTER PROFESSIONAL AUTOMATIC MK. IV, Ref. 176.009- 1974
http://www.omegawatches.com/spirit/history/vintage-omegas/vintage-watches-database?ref=14296

Both of them cost about 1800 Euro. Both watches have been repaired and are selled with a 6 month warranty.
However, I am not an expert concerning vintage omega watches. Therefore, I would be greatefull if somebody could give me an advice.
Witch of the two watches would you recommend to buy? Are they more or less the same? Or has one a much higer resale value? And what about the price? Is 1800 euro too much for an revised MARK IV? How much would you pay?

Thank you very much for your help,
Best,
Michael
Michael