From some shots pc-98 looks to outclass the 88. I will say when I ran the FM-Towns emulators for the Marty it looked pretty good. I'll check the specs of each in a bit since poking around has had some decent results. Translations on these machines I have no clue on difficulty. Its a damn shame many titles across all platforms didn't have more translations. Some are pretty bad and need amending. You're damn lucky to get voice actors and even more rare GOOD voice actors. Musicals score never seem to have goid translations. The language barrier can only be broken down so far.
PC-98 is a stronger machine -- even on the surface level it has higher resolution (640x400 vs 640x200 on PC-88) and more colors on screen (16 colors with a huge number of colors to choose from vs predetermined 8 colors on PC-88).
Hacking old Japanese PC games is tricky.
On one hand, text is easily accessible in most games, as it's stored in plain text (Shift-JIS encoding). On the other hand, the amount of space available to you is very low. Quite a few PC-98 games have support for half-width characters, which effectively doubles the amount of space you can use, but when there's no such thing (e.g. PC88, which mostly uses half-width romaji and katakana), you're out of luck, especially if you want to deliver something that doesn't resemble a bad localization from the early console days. That is, unless you're good with asm and willing to rework the game code...
From what I've gathered from my tests, support for half-width characters in FM Towns games is somewhat buggy and unpredictable, which explains the suspicious lack of (known) translations for this platform. My attempts to translate ElmKnight a few years ago (together with
Helly, who is a big bro) proved to be problematic, but I'm willing to give it another go when I can afford to take time off from my day job. And before you ask -- the text is compressed in the PC-98 version...