My goals:
To get to learn how to use Digital oscilloscope;
Repair mainly TVs, laptop and desktop MBs:
Frankly, many things happening in (digital) TVs as well as on notebook or desktop mainboards will be out of reach for either scope. Clock rates for CPU and RAM are way too fast, as are the modern serial buses (PCI, USB, SATA...).
You can still use an entry-level scope to check out the power supply, as well as slower serial buses in a TV (I²C, maybe SPI if used). And of course you can use the scope as a learning tool.
For frustration-free learning, the Rigol is probably the better choice than OWON or Hantek -- if only because it is more popular, so it is easier to find advice online.
Actually, I would strongly encourage you to spend even a bit more and get a 4-channel scope; they give you much more flexibility. Maybe you can find a good deal on a used Rigol DS1xx4Z or Siglent SDS1xx4X-E. I would expect that quite a few hobbyists are getting ready to replace theirs by the new generation of 12-bit entry level scopes, Rigol's DHO800 or Siglent's SDS800X HD, and may try to sell their old 8-bit scopes.
Those 8-bit 4-channel scopes are also still available new, but I would not recommend them since they seem too expensive vs. their new 12-bit siblings. When looking for used models, they should sell for significantly less than the current new price. If you can afford one of the 12-bit models, that' an even better choice of course. But these (only available new today since they were only released recently) may be outside of the price range you are comfortable with.
All mentioned 4-channel scopes, 8 and 12 bit from Rigol and Siglent, are easily hackable to higher bandwidth by the way.