Taking a wild punt at your present situation, It seems to me, there is a desire to experience a Cartridge, and it is quite important to you as there is a wish to get the best from your Phonostage for the foreseeable future.
I would not spend big on a Cartridge at present, if a Cartridge requires replacing by all means seek out a new Cartridge out. A prudent choice at this stage will allow you to experience a MC Cartridge for the next few years, that can offer to you the impression a valuable upgrade has been made. If it is a very much enjoyed Cartridge and used regularly, it might be well on its way to needing to be replaced when your next phase of acquisitions materialize.
When making the provision for the funds to replace the TT > Tonearm, pencil in a allowance for a Cartridge of choice and there is time on your side to make that investigation and decision about the Cartridges on your shortlist.
I don't usually recommend a Brand, but recently, I have been seeing Vinyl Enthusiasts move onto the SKY ANALOGUE (SA) range of MC's, and more recently, I have seen their entry level model, Supersede the use of a Hana MC's in another systems.
The ( SA ) entry level will not break the bank and leave change to go into the kitty for future plans if the Hana is not chosen.