I am looking for a product that can seal cracks, like an epoxy injection, that is also waterproof, but here's the kicker..........I'm looking for something with a high viscosity.
called "186 Healer/Sealer" is applied to slab surfaces via squeegee etc after surface prep. A broadcast of sand is applied prior to drying to avoid a slippery surface.
It does penetrate top surface cracks via gravity, but the depth of penetration is very dependent on the crack width and the cleanliness of the crack. It does NOT replace crack repair via epoxy pressure injection.
If you want to seal wet cracks (leakage injection) then you can use a combination of Nitofill UR63 (70%) / Nitofill WS60 (30%) and both these products are from FOSROC. To seal DRY cracks you can use Nitofill EPLV from Fosroc.
Equivalent products in BASF are Concresive 1320 / 1335 for wet cracks and Concresive 1315 for dry cracks.
Remember all these products can ONLY be injected and not just roller applied or painted on crack surface.
Your requirements are at odds with each other. If the material is highly viscous, it will not likely penetrate cracks except very wide ones. If it is thin enough to penetrate cracks, it will serve only as a surface sealer, not a coating.
Decide which is more important and then select the proper material for the application. You might end up using two different materials, applied separately.