Hi,
As Xavier said, using options and custom fields can allow you to handle many choices, even more than what you need. The thing though is that options and custom fields are different than caracteristics.
The caracteristics system creates one variant of the product for each combination of values of the caracteristics (which amounts to a lot of data and thus the crashes on your server). Options and custom fields don't work like that and thus you won't get the issue. But then you can't assign one price for each combination. With options you can set the price of each choice and it adds up to the base price of the product. With custom fields, you can't change the price. Of course, you can have a combination of characteristics, options and custom fields on your products based on your needs, so I guess that it will resolve the problem if you use the Business edition since you'll be able to replace some of the characteristics with options/custom fields.