Best practice for ASP.NET MVC webshop search-engine with SQL Server database

Question

We developing a webshop with a SQL Server database in the background and have an internal discussion about the best way to integrate/create a search engine.

At the moment we discuss following approaches:

1. SQL Server full-text search

   • PRO: Fast!
   • CON: often bad results, because of language problems (german) or technical abbreviation,...

2. Lucene.Net

   • PRO: Fast, good results..
   • CON: Outdated (last release 3.0.3 - Oct 10, 2012) ???

3. Web caching (HttpRuntine.Cache) / Linq searching (was only an idea to cache all search data via hangfire framework and make a classic linq search)