Build Up to a Gaming Weekend

A few months ago, I discovered that a friend of mine from college plays 40k when I stumbled on a review he wrote for a gaming store 200 miles from my house. We had honestly not been in touch much since college but, when I dropped him a line to tell him I would be swinging by the shop on my way through his area, we quickly arranged to meet at the shop and catch up.

An epic game of Apocalypse going on at the store when we met

As we talked, he told me he played Tyranids and Space Wolves. Coincidentally, our mutual friend, Chandler, who got me back into the hobby also played Space Wolves. After a while of sharing stories and astonishment that we never had a clue that each other played the game, we decided we'd have to set up a weekend for him to visit and have a big game with the three of us.

After a couple delays and scheduling difficulties, our appointed weekend less than two short weeks away. Early on we decided that the big highlight of the weekend was going to be a 4k game, with Chandler fielding 4k of his Wolves and any allies he so desires facing off against our friend and I, each fielding 2k of 'nids.

In the next two weeks, I will be trying to accomplish several things in preparation for the weekend. For one, I would ideally like to have my full 2k list painted. Here is my planned list and their state if unpainted, crossed out if completed:

Swarmlord: in pieces and primed, 10% complete on the carapace
Tyrant Guard
Flying Hive Tyrant w/2 TL Devourers
2 Zoanthropes: 1 painted poorly, 1 primed red, but I need it black
2 Hive Guard: 3 in pieces, needing to be primed but cleaned of flash
Deathleaper (being represented by a 3rd ed Lictor)
19 Termagants w/Devourers: 12 painted, 8 more primed
Mycetic Spore: various rough attempts lying around in ugliness - 3 styrofoam, one attempt with sculpey
Tervigon
20 Hormagaunts w/Toxin Sacs: ~16 painted, though 4-6 are snapped off their bases, another 20+ still on sprues
7 Genestealers including a Broodlord: 10 old stealers painted, Space Hulk 'stealers and broodlord awaiting assembly
Trygon Prime

If I get close I might swap some things around to make it, but this definitely looks like a tall order for the next two weeks, particularly given my current pace (or lack-thereof) for painting.

Secondly, and possibly more importantly, while I have a painted 4'x8' playing surface, I have a distinct lack of terrain. In the past we've made do with carboard or paper cutouts representing forests or area terrain, some styrofoam walls, etc. I really would prefer to not settle for that in this game, partly so I can get some great pictures to show here. Considering the size of the table, I want to shoot for at least 18 pieces of "significant" terrain. By significant I mean large ruins, buildings, woods, or tall hills, with smaller pieces combining into one piece of significant terrain.

What I have done:
2 Swamps/ponds about 4"x12"
1 (GW-Made) Ruin about 8"x14"

 

What I have planned/partially constructed:
2 (GW) Ruin corners - need to be mounted on a single base and painted
1 Plastic building/factory
2+ Area Woods using old plastic trees from the 3rd edition box on a base, possibly magnetized for ease of use.
2+ Styrofoam layered hills
1+ Foamboard buildings/ruins
Maybe 1 Statue using an old Inquisitor-scale model (if I can find it)

That, to me, looks like a lot of work and yet doesn't even get me close to my goal of 18 pieces of terrain. Does anyone have any suggestions for some sizable terrain pieces that can be made fairly quickly by a terrain-idiot?