even $50 DDS have option to upload waveform, you need software related to generator and PC to make waveform and upload.
some models can store a few, some many.
your requirement to generate signals quite low, and any DDS generator can do this, starting from lowest 30-50 dollars
you may very satisfied with 15 Mhz version ; portable option DDS.
https://vi.aliexpress.com/item/1005006869830606.htmlget some expedience and figure out better requirement for a future; or maybe you will satisfy and get more gens like this to simulate 4 or 6 channels ...
gettin $500 are nice , but just overkill for you need ,