When restoring SQL recreates the DB exactly as it was at time of backup, including file sizes. So you will need space for the full size of the original DB.
That the log is way bigger than the data file suggests missing log maintenance. Please read through this - Managing Transaction Logs[/url]
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability