In terms of bang-for-buck you cannot beat Rigol right now:
http://www.saelig.com/product/PSPC017.htm ** The oscilloscope you linked is the 50Mhz version of this scope. Get the 100Mhz one! **
http://www.saelig.com/FGDG/FGDG007.htm
But you may not want a function generator at all. BTW, the top frequency for the generator you linked is 200Khz for sine wave and 10Khz for the other. That is very low. There are some very cheap kits, many already built, just no enclosure so they are kit-like, to do various waveforms on eBay. These kits are not as good as the Rigol above and nowhere as friendly, but you can get the signals you need out of them. Some examples:
http://www.ebay.com/itm/AD9850-DDS-Signal-Generator-Module-0-30MHz-Sine-Square-Wave-Frequency-AD9851-/330621540938
http://www.ebay.com/itm/50MHz-Sine-Wave-5Mhz-Square-Wave-DDS-Signal-Generator-with-Sweep-Function-NEW-/320897517771
http://www.ebay.com/itm/Wave-Signal-Generator-Module-PWM-Sine-Wave-Square-Triangle-Saw-tooth-etc-300kHz-/330760676635
On the specs page for the DSO nano I see that the ADC they are using is 1 MSPS. The cheap Rigol, for example, is 1000 MSPS. All I can say is that the DSO doesn't look all that appropriate for high-speed circuits (it tops out at 1Mhz and does that on 1 MSPS which is cheating). It seems more suited towards audio gear.