Sorry, but I don't own a Lakland bass. Why? Let's just say that the folks at Lakland and I, are not on cordial speaking terms - and let it go at that... However; all but 2 of my 24 bases wear flats of some kind - including my 3 active basses (an Alembic Epic; an EBMM 4HH Stingray Special; and a Tom Hamilton Sig. G&L ASAT Bass).So... what flat wounds should you use? That's completely up to you - and the kind of music you like/want/need to play. Flatwounds run the gamut; from pure, Low End Thump, through mid-rangy, "modern" tones; to "Are you sure these are
flats?" bright. I don't like really bright flats, myself, although I do have the 39-96 La Bella 760 Flats on a couple of my Danelectros - for the Vintage, twangy "Dano Sound". Which I doubt you'd want from a Lakland...
My 3 active basses all have midrange-y, "Modern" flats. Because I have so many basses, most of them are set up as
"one Trick Pony's". But, that seems like a waste of an active bass, so they're set up to be versatile. The Alembic wears TI Jazz Flats. Because of the difference in stiffness, the Alembic is the only bass that always gets finger-picked. The Stingray Special wears Galli Jazz Flats; very, very smooth, and IMO? A little on the "low end" of the midrange category. Definite low end; good low-mids and mids; and also a useful top end, too. The G&L ASAT Bass? It wears probably my favorite flats; Fender 9050Ls. IMO, they define the mid-range, Modern flats category. Every other flat I've ever played (and in 50+ years of playing flats? I've played a lot of them) has been either brighter than the 9050s - or thumpier. I've had them on as many as 5 basses at the same time, but the only bass with them at the moment, is the G&L ASAT...
As for the Low-end Thump? Most La Bella DTF's are the default strings for that, but the heavier GHS Precision Flats (which I have on both my long- and short-scale Precision Basses) will work just fine, too. Pyramid Flats are supposed to be very thumpy (never tried them, though), and Roto RS77LDs, although I'd consider them the thumpiest of the Mid-range Flats, will work, too. They were awesome on my '18 Gibson Thunderbird...
So, bottom line? It depends on the tone you want from your bass. Decide what you want to hear from that bass - and choose accordingly...
sound