I agree with Shane. There's a rich variety of four aspect signals making use of Bloodnok's target-based signalling system (so they can show feathers and theatre indications). The one's I've got include:
sig 4a dorman LH standard round post,<kuid:45317:1261>
sig 4a dorman RH standard round post,<kuid:45317:1580>
sig 4a dorman LH Tunnel floor mounted,<kuid:45317:2175>
sig 4a dorman RH Tunnel floor mounted,<kuid:45317:2553>
Sig 4A Gantry OHL (modified trackside),<kuid:45317:2565>
sig 4a 1970s gantry non elec,<kuid:45317:104320>
NEX 4asp Invisible signal,<kuid:45317:104689>
sig 4a WR 1960s 4m tall LH,<kuid:45317:105086>
sig 4aC WR 1960s 4m tall LH,<kuid:45317:105102>
Sig 4a WR 1960s 4m no.4RI+RHsub (xbge yd),<kuid:45317:105105>
Sig 4a WR 1960s 4m no.1RI+LHsub (xbge yd),<kuid:45317:105110>
Sig Duchy 4ACH BR Post Std LHS,<kuid:45317:105164>
Sig 4AT BR Post Std LHS,<kuid2:60850:24007:3>
Sig 4A BR Post Std LHS,<kuid2:60850:24009:3>
Sig 4AT BR Post Std RHS,<kuid2:60850:24017:3>
Sig 4A BR Post Std RHS,<kuid2:60850:24019:3>
Sig 4A BR Platform Post Std LHS,<kuid2:60850:24029:3>
Sig 4A BR Platform Post Std RHS,<kuid2:60850:24039:3>
Sig 4A SR Cantilever Span LHS,<kuid2:60850:24049:3>
Sig 4A BR(S) Cantilever Sighting LHS,<kuid2:60850:24059:3>
Sig 4A BR(S) Cantilever Span LHS,<kuid2:60850:24069:3>
Sig 4A BR(S) Cantilever Sighting RHS,<kuid2:60850:24079:3>
Sig 4A BR(S) Cantilever Sighting platform LHS,<kuid2:60850:24089:3>
Sig 4A BR(S) Cantilever Sighting platform RHS,<kuid2:60850:24099:3>
Sig 4A SR Cantilever Sighting LHS,<kuid2:60850:24109:3>
Sig 4A SR Cantilever Sighting RHS,<kuid2:60850:24119:3>
Sig 4A BR Platform Post Offset LHS,<kuid2:60850:24139:3>
Sig 4A BR Platform Post Offset RHS,<kuid2:60850:24149:3>
Sig 4AT BR Post Elec Dbl LHS,<kuid2:60850:24157:3>
Sig 4A BR Post Elec Dbl LHS,<kuid2:60850:24159:3>
Sig 4AT BR Post Elec LHS,<kuid2:60850:24177:3>
Sig 4A BR Post Elec LHS,<kuid2:60850:24179:3>
Sig 4A BR Post Elec RHS,<kuid2:60850:24189:3>
Sig 4AT BR Post Offset LHS,<kuid2:60850:24197:3>
Sig 4A BR Post Offset LHS,<kuid2:60850:24199:3>
Sig 4AT BR Post Offset RHS,<kuid2:60850:24207:3>
Sig 4A BR Post Offset RHS,<kuid2:60850:24209:3>
Sig 4A BR Post Round Head LHS,<kuid2:60850:24259:1>
Sig_4A_Gantry_OHL,<kuid2:125145:24003:2>
Sig 4A Gantry,<kuid2:125145:24013:1>
So you can see there's a good choice!
Paul