There are some reservoirs where you can just simple screw the pump in.
http://www.frozencpu.com/products/11220/ex-res-233/XSPC_Tank_Reservoir_-_Laing_D5_MCP655_w_Blue_LED_Light_-_Acrylic.html?tl=g30c97s152
http://www.frozencpu.com/products/7272/ex-pmp-63/XSPC_Laing_DDC_Reservoir_Pump_Attachment_w_MCP-350355_No_Fittings.html?tl=g30c97s152
And then there are more elaborate mounting kits that are a bit more complex but look better. For instance if you use a D5 pump in conjunction with an aftermarket Bitspower head, you can then mount a Bitspower reservoir on top using this kit.
http://www.frozencpu.com/products/14208/ex-pmp-167/Bitspower_D5_MCP655_Pump_Mod_Top_V2_-_Acetal_G14_VersionBP-D5TOPP2-BK.html?tl=g30c107s1805#blank
http://www.frozencpu.com/products/16076/ex-res-369/Bitspower_Dual_Single_D5_Top_Upgrade_Kit_250_-_Black_BP-D5TOPUK250P-BKBKCL_.html?tl=g30c97s152
However if those canned solutions aren't to your liking (or budget), then you can always jury rig the reservoir on top of a pump.
This is where clever use of adapters comes in. Get a double sided male G1/4" fitting, screw it onto the bottom of the res, and you should just be able to screw the reservoir into any G1/4" fitting on the pump.
http://www.frozencpu.com/products/11882/ex-tub-732/Bitspower_G_14_Matte_Black_Male_to_Male_Rotary_Extender_BP-MBRG.html?tl=g30c497s1362
Obliviously you want to make sure both are adequately supported. As I don't think a single G1/4" fitting will hold up a tube reservoir full of water.