JAque,
With 401K funds from previous employers you should have it managed by someone that will let you diversify your capital into any investment. If you have over 100K from previous employers you should have the option of investing in your choice of stocks and bonds. The problem with most mutual funds is the management fee charges can absorb your profits. Usually, the mutual funds with the lowest management fees are index funds. I suggest these as your investments if you do not have the time to manage your money. The majority of stock funds underperform the index funds which makes the index fund a good investment. In order to pick a stock fund that does better than the index fund (plus consider management fees added) you will have to do your own research on the fund. Most employers stock funds are publically traded. You can look at their performance by using several free sites like
www.quicken.com to compare them to the indexes.
With your current employer fund options you should be able to do some research to figure out which cost less to maintain and perform better.
Good Luck
Mark