Sorry to disagree, fellas, but I think Shadowcat is totally in the clear with this thread. There is a very distinct question in here as he's looking to go all infantry. Of the two "redundant" threads, one's about modelling and the other quickly degenerated into that nonsense about MEq killing and how useless statistics are in statistical wargames (in addition to the usual nonsense about sharpshooters).
This question, on the other hand, asks for thoughts on heavy weapon deployment without the usual options (Basilisk, LR, other tank-like goodies).
My personal opinion is that pure infantry succeeds by putting an obscene number of wounds on the table. However, against certain enemies, this will present real problems as the most point efficient wounds you can buy are conscripts and line squads. This means you'll be unable to concentrate heavy fire and will waste shots every turn one way or the other. The best way around this is to group like weapons (meaning HB/GL in line squads and AT squads of LC/ML) so you don't waste shots. Unfortunately, this means your heavy weapons are expensive and vulnerable, which is counter to all-infantry goals. One compromise configuration at lower points (>150
is maxxed lascannon vet squads and maxxed grenadier troop choices (2x PG) and plasmagun line squads (with or without a heavy weapon). The LC vet squads have good wound coverage and BS while every line squad has a versatile weapon that can whack up to AV 13.