The regular 821RC_q_image.tgz works in the sim. It may fail due to timeout because the sim is rediculously slow, and it may fail if you don't have a large enough root volume (1gb is not enough).
vSIM80::> system node run -node local sysconfig -av
NetApp Release 8.2.1RC1 Cluster-Mode: Wed Nov 20 15:25:04 PST 2013
System ID: 4034389062 (vSIM80-01)
System Serial Number: 4034389-06-2 (vSIM80-01)
System Storage Configuration: Multi-Path
System ACP Connectivity: NA
slot 0: System Board 2.3 GHz (NetApp VSim)
Model Name: SIMBOX
Serial Number: 999999
Loader version: 1.0
Processors: 2
Memory Size: 1599 MB
Memory Attributes: None
slot 0: 10/100/1000 Ethernet Controller V
e0a MAC Address: 00:50:56:9e:9c:09 (auto-1000t-fd-up)
e0b MAC Address: 00:50:56:9e:ca:c1 (auto-1000t-fd-up)
e0c MAC Address: 00:50:56:9e:e0:e9 (auto-1000t-fd-up)
e0d MAC Address: 00:50:56:9e:c3:eb (auto-1000t-fd-up)
e0e MAC Address: 00:50:56:9e:ff:84 (auto-1000t-fd-up)
e0f MAC Address: 00:50:56:9e:9a:f9 (auto-1000t-fd-up)
Device Type: Rev 1
vSIM80::>