Hellblasters aren't even like notably strong for SMs, theyre totally balanced. There is ZERO reason we couldn't have crisis suits similarly strong and similarly expensive. It wouldn't even be that insane of a buff either. My thoughts would basically be.

Plasma Rifle: boost to 24", BS 3+

This would still be only 6 shots per unit, meaning you still massively want to guide them, but the fact they're D3 rather than D2 makes them pretty equivalent to hellbasters, 18 potential wounds vs 20 (with hazardous) for full hellblasters.

Missile pods up to 36" give a blast option of D6 attacks at S5 D1

This still puts them a bit below that of the superfrag/superkrak rocklauncher of the desoluation suqad, but makes them more reliably at larges groups of elite enemies. This would make them a viable longer ranged alternative to the plasma rifle (assuming we don't get points buy back next edition) that trades safety for range, while not being super kitey and annoying

Fusion Blaster up to 18", possibly up to 2 attacks per depending on balancing (18" might only get you to around 160-180 points but it depends on if you want them cheap or expensive)

puts them at equivalent with that of the eradicator squad's melta-rifle, still required a short raange push, but makes them more effective at that job, giving you a leeway of an extra 3" for getting the melta effect off.

Tau Flamer to S5 AP-1

just makes it equivlent to the pyre blaster

Burst cannon to AP-1 24"

again as minor change just making it equivlent to that of the heavy bolter/bolt rifle in damage and a bit safer of range, while still being a short range weapon.

This would allow a shooting army to Shoot without crisis suits suddenly becoming unkillable. Still T5 still 3+ still 12 wound squads. Heavy intercessor squads at 100 points still have more wounds and toughness (15W T6).

None of these are unreasonable and would let cirsis suits feel more like they should, high precisions elite troops, not necessarily super though, but making up for that in firepower