2.6m of head is OK, 600lph is with no restriction which obviously won't be the case with two blocks and maybe two rads. Why do you need two by the way? Seems like overkill!
Less head than a DDC 10W (3.3m) but more flow (440LPH) but way less than an 18W which does 4.7m with 600lph. And that's with the standard top rather than one of the better after-market ones.
To my mind, the pump is the one area not to scrimp on because a good one will last you for years and see you through several upgrades. Get a DDC Ultra with an XSPC res-top. More money but much better option.