Travel pack with wheels ie suitcase with straps

All I would say is that the addition of wheels also adds (sometimes considerably);to the weight of the bag.
Do you really need both options? Or could you choose whether a lighter backpack OR a wheeled suitcase could be your best option.

I check in a wheeled suitcase for longer holidays but have been trying to source a set of 2 light wheels to strap onto my hand luggage for a quick trip instead of using my heavier wheelie bag. No luck so far but I am sure they used to be available. Any ideas?

Suitcase with straps = backpack with wheels.
Look up rolling backpacks, come in all sizes.

I had one, the frame which held it rigid so it could be wheeled made it very uncomfortable on my back (tbh I've never found backpacks comfortable even in my hillwalking youth). You need 4 wheels or it's a pain to roll. I wheeled mine far more than I carried it, when l did carry it l mainly used the carry handle. I used it for one trip and wouldn't buy one again,